The Flow Cytometry Core will be an integrated and essential component of the proposed RDRCC. The flow core will support cutting edge work on rheumatic diseases and other related immune/inflammatory disorders including immune mediated lung injury, immunology of frailty, immediate hypersensitivity and bacterial and viral induced chronic disease. The overall goal is to provide cell sorting and polychromatic flow cytometry services for a range of research initiatives including complex immune phenotyping of samples from human rheumatic disorders, investigations on the antigen driven response in human disease, basic studies on the signals that influence Immune cell differentiation and function and the development of animal models of human disease. In the next five years of the RDRCC we propose the followings three aims for the Flow Cytometry core: 1. Provide RDRCC investigators access to state of the art flow cytometry instrumentation and methodology. This includes ready access to technology, expertise and training. 2. Provide a range of flow cytometric based procedures that will enhance and expand the research programs of RDRCC investigators. 3. Attract new investigators to utilize the flow core by providing a collegial environment, through targeted outreach and by providing educational opportunities for investigators at all levels.